I’m forever on the prowl for ways to make fish enticing for my family. This simple method does the trick. Red miso (soybean paste) and pineapple juice combine to make a flavorful, quick marinade. Meanwhile, fresh pineapple slices and scallions go on the grill. It all takes about 30 minutes from start to finish.

You’ll want to move fast; if you let the fish marinate too long, its texture will deteriorate. Also, the fish cooks very quickly on the grill, so be attentive.

Red miso is available in the refrigerated case of most Asian markets and many organic foods markets. It brings a deep umami flavor: sweet, salty and sour.

Prepare the grill for direct heat. If using a gas grill, preheat to medium-high (450 degrees). If using a charcoal grill, light the charcoal or wood briquettes; when the briquettes are ready, distribute them on one side of the cooking area. For a very hot fire, you should be able to hold your hand about 6 inches above the coals for 3 or 4 seconds. Have ready a spray water bottle for taming any flames. Lightly coat the grill rack with oil and place it on the grill.

Whisk together the miso and pineapple juice in a small bowl until smooth. Place the cod fillets on a large plate or piece of aluminum foil. Brush the marinade all over the fillets, coating them completely. Let the fish rest for 15 minutes.

Meanwhile, lightly brush the pineapple slices and scallions with the vegetable oil. Transfer them to the grill. Close the lid and cook, turning once or twice, until the scallions have good grill marks on two sides — 3 to 5 minutes, depending on the thickness of the scallions. The pineapple should cook a little longer, 7 to 8 minutes, until it softens and good grill marks appear. Transfer the pineapple slices to a plate; when they are just cool enough to handle, cut them into 1/4-inch dice. Use kitchen scissors to cut the scallions into 1/4-inch pieces.

Combine the pineapple, scallions, the 2 tablespoons of vinegar and the teaspoon of toasted sesame oil in a bowl. Season lightly with pepper. Wait a few minutes, then taste and add vinegar, toasted sesame oil or salt, if using. Cover to keep warm.

Brush any excess marinade off of the cod fillets and transfer them to the grill. (Discard all of the marinade.) Close the lid and cook for 3 to 4 minutes, until the fish is nicely browned. Use a thin spatula to loosen the fillets and turn them over. Cook for 1 minute (thin fillets) or 2 to 4 minutes (thicker fillets).

Divide the fillets among individual plates. Spoon the pineapple-scallion relish on top of or alongside the fish. Serve right away.